Apparatus for mixing fluids



Patented Jan. 8, 1946 APPARATUS FOR mxnsc FLUIDS Maryan P. Matuszak,Bartlesvllie, Okla, assignor to Phillips Petroleum Company, acorporation of Delaware Original application October 5, 1942, Serial No.

1943, Serial No. 494,868

6 Claims.

This invention relates to improvements in apparatus for mixing fluids,more particularly to improved apparatus for conducting chemicalprocesses involving adding continuously at least one fluid to a zonewherein it is rapidly mixed with the contents already present in thezone, and still more particularly to improvements in apparatus forconducting a chemical process such as an alkylation process involvinintroducing one or more fluid reactants to a reaction mixture underreaction conditions;

In many processes, mixing of fluids is desirable or necessary. When thefluids are mutually chemically inert during the mixing, so that theproduct is merely a physical mixture or emulsion of the original fluidswithout these fluids being changed chemically, the precise manner ofbringing the fluids together may be relatively unimportant; that is,provided that the final proportions of the 'fluids are within certainlimits, the nature and composition of the product may be relativelyindependent of such factors as the order of bringing the fluidstogether, the rate of mixing, and the like. When, however, the fluidsare mutually chemically reactive, and especially when one or more ofthem can undergo more than one chemical reaction, the precise manner ofmixing may be very important in determining the nature and compositionof the product.

Although certain aspects of the present invention may be applied to themixing of any fluids whatsoever. some of its aspects are particularlyadvantageous for mixing liquids that undergo chemical reaction,especially a chemical reaction that competes with one or more otherreactions and that proceeds most desirably if the concentration of onereactant is kept as low as possible. The inventionmay be applied toreactions conducted in a batch-wise manner, but it is most useful whenapplied to reactions conducted in a continuous manner.

An object of this invention is to provide an improved apparatus formixing fluids.

A specific object of this invention is to provide improved means formixing mutually chemically reactive fluid reactants under reactionconditions in such manner that the relative concentration of a selectedreactant is minimal.

Another specific object of this invention isto provide improved meansfor rapidly dispersing a first liquid reactant in a reaction zonecontaining a second liquid reactant, whereby a desired reaction betweenthe two reactants is favored, and

one or more competitive reactions consuming the first liquid reactantare minimized.

Divided and this application July 15,

, Another specific object of this invention is to provide improved meansfor conducting the alkylation of an alkylatable hydrocarbon with: analkylating agent or alkylant in a zone in which suitable conditions aremaintained for the alkylation in the presence of a mobile alkylationcatalyst, whereby the alkylation is favored, an competitive reactionsare minimized.

Another specific object of this invention is to provide improved meansfor the production of alkylated compounds.

Another specific object of this invention is to provide means foreffecting cooling of an alkylation reaction mixture while at the sametime recovering in purified condition at least part of a volatilealkylation catalyst contained in the alkylation reaction mixture.

Other objects and advantages of this invention will be apparent to thoseskilled in the art from the following description, the accompanyingdrawing, and the appended claims.

In one specific embodiment, this invention comprises means whereby .atleast one of two or more fluids is introduced into a mixing zone throughone or more openings that are in continuous motion with respect to themobile contents of the zone, the openings being preferably so located inmoving devices for imparting vigorous turbulent and/or circulatorymotion to the contents of the zone that relative movement of thecontents of the zone past the openings occurs at relatively highvelocity. Examples of such moving devices are impellers, propellers,other mechanical agitators of various types, and the like. If desired, apart of the total fluid being introduced into the mixing zone may beintroduced through openings in selected stationary spots at whichmovement of the contents of the zone past the openings occurs atrelatively high velocity; such openings may be in, for example, guidingand/or turbulence-aiding partitions, fins, bafiles, other protuberancesof various types, and the like. For removal of heat from the resultingmixture, evaporative cooling may be practiced.

tated by reference to the accompanying drawing, in which, Fig. 1 is adiagrammatic section of one illustrative form of mixer or reactorembodyin certain specific aspects of the invention, and Fig. 2 is asectional view on the. line 22 of Fig, 1.

In Fig. l is shown a vertical diagrammatic section of one form of mixeror agitator constructed in accordance with the present invention. Itwill be understood that Fig. 1 does not purport to show the mostdesirable dimensions and/or pro- Understanding of this invention may befacilithose shown in Fig, 1 may be used, provided only.

that they perform substantially the same functions as those specificallyshown or described herein.

The reactor illustrated in Figs. 1 and 2 is a generally cylindricalshell 3 closed at one end by bottom 4 and at the other end by detachablecover 5, which may be attached to shell 3 by any suitable means, as by aflange-type joint with suitable clamps or bolts. Shell 3 is providedwith any desired number of inlets and outlets, exemplified by inlet I6and outlet 21.

Cover has incorporated with it packing gland or stumng box 22 aroundrotatable shaft 23, which is provided with one or more sets of stirrer,impeller, or propeller vanes or blades 6, designed or shaped so as notonly to agitate the contents of shell 3 but also to cause internalrecirculation.-

Shaft 23 has an internal passageway I, which communicates on the onehand through space 8 with inlet I4 and on the other hand through one ormore orifices 26 with mixing and/or reaction zone 9 defined by shell 3,bottom 4, and cover 5;

passageway I is advantageously used for the inrapid dispersal ofmaterial passing through them into zone 9; usually they are preferablymuch smaller in diameter than passageway I and are further preferably ofa Jet-like construction. They are preferably located at the points instirrer blades 6 at which maximal contact with the mixture in zone 9 perunit time is effected, but they may be located otherwise than asspecifically shown.

Leakage around shaft 23 below space 8 is prevented by packing I09,suitably graphited asbestos or the like, housed in the upper part ofgland 22. This packing may be compressed to any desired extent byccmpressionmember IIO, which cooperates with gland 22 through atightening means exemplified by rotatable annular ring I I I cooperatingwith gland 22 as by threads II2. Packing I69 is advantageously protectedfrom the mixture in zone 6 by the sweeping passage of materialrelatively inert to the packing, such as an alkylatable hydrocarbon,from inlet II through annular space I I3 between shaft 23 and apron 25into. zone 9. Leakage around shaft 23 above space 8 is similarlyprevented by packing III, housed in the upper end of compression memberH0, which at this point is similar in function to the upper part ofgland 22. This packing may be tightened or compressed to any desiredextent by tightening member H5, which cooperates with the upper part ofmember H0, as through screw threads H6, in a manner well understood inthe art. It will be understood that the arrangement shown in Figure 1 isschematic and that various known modifications, such as for example theuse of lantern glands and of forced lubrication of shaft 23 at points incontact with packings I09 and Ill, may be practiced wheneveradvantageous or convenient.

Cooperating 'in the mixing function of rotating vanes or blades 6 may beone or more sets of stationary vanes II'I, angularly spaced andcorrespending in number and vertical spacing to blades 6, supported asfrom cover 5 by supporting members I I6 which are shown as rod-like inform but which may be an annular member. One of members I I8 is shown asbeing provided with passageway H9 for introduction of one or morereactants, or of the catalyst, from inlet I20 through orifices or JetsI2I in vanes I I1. into zone 9, in the manner already indicated. Theorifices I2I may desirably be substantially smaller in diameter thanpassageway H9, as before. If part or all of an olefin or other alkylant'is introduced into zone 3 through orifices I2I, the catalyst should beintroduced through some other inlet, such as inlet I3.

As an example of the alkylation of a relatively readily alkylatablehydrocarbon may be taken the continuous alkylation of benzene witholefins in the presence of concentrated or anhydrous hydrofluoric acid.The hydrofluoric acid is introduced, as through inlet I6, into thealkylator, "which is preferably provided with a single or multipleagitating unit of the turbo-mixer type; after a steady state ofoperation is reached, only makeup acid to replace lost acid and acidwithdrawn from the system is added throughinlet I6.

Benzene is added, as through inlet II, to the alkylator in a mannerdesigned to protect the packing around the rotating shaft of theturbomixer unit, passing from this packing toward the interior of thealkylator as within apron 25. Most of the benzene going to thealkylator, however, is passed in admixture with the alkylating olefinvia inlet I 4 through the passageway I in shaft 23 of the agitating unitand into the reaction zone through jet-type openings 26 at points in theunit having relatively high linear velocities, as at the extremities ofthe blades of this unit. There-, by an extraordinarily rapid dispersaland mixing of the incoming feed with the already present and internallyrecirculating mixture of hydrocarbons and hydrofluoric acid is obtained,with a resultant extraordinarily high alkylation efiiciency, so that theconsumption of olefin by reactions other than alkylation is negligibleor virtually nil. One component of the reaction mixture may beintroduced via inlet I20 and jet orifices I 2| if desired. The reactionmixture may be withdrawn through outlet 21.

Because the invention may be practiced otherwise than as specificallyshown herein, and because many variations and modifications of itwill 1. Apparatus for carrying out a chemical reac tion involving aplurality of fluids and for intimately mixing said fluids during saidreaction comprising stationary enclosing means forming a closedrelatively large mixing and reaction zone and comprising a container anda cover therefor,

' inlet means connected to said stationary means tending downwardlythrough said cover into said container, a plurality of vertically spacedoutwardly extending mixing blades rigidly mounted on said shaft withinsaid container, a passageway in said shaft extending from an inlet pointat the surface thereof located above said cover axially downwardly andthen outwardly through said mixing blades to the ends thereof, a membersurrounding said shaft and forming an annular space surrounding saidinlet point, an inlet conduit connected to said member and to saidannular space, sealing means located above said inlet point and saidannular space for sealing said shaft'with respect to said annular space,common sealing means below said inlet point and said annular space forsealing said shaft with respect to said annular space and also forsealing said shaft with respect to said cover, and a plurality ofvertically spaced stationary horizontal vanes supported by said cover,said vanes corresponding in number and vertical position to said mixingblades and located Just outwardly of the tips of said mixing blades,said vanes being angularly spaced in their annular relationship to saidmixing blades.

2. Apparatus for carrying out a chemical reaction involving a pluralityof fluids and for intimately mixing said fluids during said reactioncomprising stationary enclosing means forming a closed relatively largemixing and reaction zone and comprising a container and a covertherefor, inlet means connected to said stationary means for introducinga reactant continuously thereto,

outlet means connected to said stationary means for continuouslywithdrawing reaction products therefrom, a rotatable stirrer shaftextending downwardly through said cover into said container, a pluralityof vertically spaced outwardly extending mixing blades rigidly mountedon said shaft within said container, a passageway in said shaftextending from an inlet point at the surface thereof located above saidcover axially downwardly and then outwardly through said mixing bladesto the ends thereof, a member surrounding said shaft and forming anannular space surrounding said inlet point, an inlet conduit connectedto said member and to said annular space, sealing means located abovesaid inlet point and said annular space for sealing said shaft withrespect to said annular space, common sealing therefrom, a rotatablestirrer shaft extending means below said inlet point and said annularspace for sealing said shaft'with respect to said annular space and alsofor sealing said shaft with. respect to said cover, a plurality ofvertically spaced stationary horizontal vanes corresponding in numberand vertical position to said mixin blades and located just outwardly ofthe tips of said mixing blades, said vanes being angularly spaced intheir annular positioning around said mixing blades, aplurality ofvertical supporting means depending from said cover for supporting saidvanes, a vertical passageway in at least one of said supporting meansleading from said cover axially downwardly of said supporting means andthen inwardly through said vanes supported thereby to the inward tips ofsaid vanes and discharging oppositely to the passageway in said blades,and an inlet conduit connected to said vertical passageway for supplyinga reactant into said reaction zone.

3; Apparatus for carrying out a chemical reaction involving a pluralityof fluids and for inti mately mixing said fluids during said reactioncomprising stationary enclosing means forming a closed relatively largemixing and reaction zone and comprising a container and a covertherefor, inlet means connected to said stationary means for introducinga reactant continuously thereto, outlet means connected to saidstationary means downwardly through said cover into said container, aplurality of vertically spaced outwardly extending mixing blades rigidlymounted on said shaft within said container. a passageway in said shaftextending from an inlet point at the surface thereof located above saidcover axially downwardly and then outwardly through said mixing bladesto the ends thereof, a member surrounding said shaft and forming anannular space surrounding said inlet point, an inlet conduit connectedto said member and to said annular space, sealing means located abovesaid inlet point and said annular space for sealing said shaft withrespect to said annular space, common sealing means below said inletpoint and said annular space for sealing said shaft with respect to saidannular space and also for sealing said shaft with respectto said cover,a plurality of vertically spaced stationary horizontal vanescorresponding in number and vertical position to said mixing blades andlocated Just outwardly of the tips of said mixing blades, said vanesbeing angularly spaced in their annular positioning around said mixingblades, a plurality of vertical supporting means depending from saidcover for supporting said vanes, a vertical passageway in at least oneof said supporting means leading from said cover axially downwardly ofsaid supporting means and then inwardly through said vanes supportedthereby to the inward tips of said vanes and discharging oppositely tothe passageways in said blades, the orifices in both said blades andsaid vanes being substantially smaller than the passageways feeding thesame and being constricted in such a way as to aid in more rapiddispersal of the material passing through them into the reaction'mixturein said reaction zone.

4. Apparatus for carrying out a chemical reaction involving a pluralityof fluids and for intimately mixing said fluids during said reactioncomprising stationary enclosing means forming a closed relatively largemixing and reaction zone and comprising a container and a covertherefor, inlet means connected to said stationary means for introducinga reactant continuously thereto, outlet means connected to saidstationary means for continuously withdrawing reaction productstherefrom, a rotatable stirrer shaft extending downwardly through saidcover into saidcontainer, a plurality of vertically spaced outwardlyextending mixing blades rigidly mounted on said shaft within saidcontainer, a passageway in said shaft extending from an inlet point atthe surface thereof located above said cover axially downwardly and thenoutwardly through said mixing blades to the ends thereof, a membersurrounding saidshaft and forming an annular space surrounding saidinlet point, an inlet conduit connected to said member and to saidannular space, sealing means located above said inletpoint and saidannular space for sealing said shaft with respect to said annular space,common sealing means below said inlet point and said annular space forsealing said shaft with respect to said annular space and also forsealing said shaft with respect to said cover, means associated withsaid cover and forming a second annular space which surrounds said shaftand is in free communication with the interior of said container, saidcommon sealing means preventing fluid from passing upwardly along saidshaft from said second annular space, and an inlet. conduit connectedoutlet means connected to said stationary means for continuouslywithdrawing reaction products therefrom, a rotatable stirrer shaftextending through said enclosing means into said zone, outwardlyextending mixing blades carried on said shaft within said zone, apassageway in said shaft extending from an inlet point at the surfacethereof located outside said enclosing means axially along said shaftand then outwardly through said mixing blades to the ends thereof, amember surrounding said shaft and forming an annular space surroundingsaid inlet point, an inlet conduit connected to said member and to saidannular space, sealing means located outside said inlet point and saidannular space for sealing said shaft with respect to said annular space,common sealing means inside said inlet point and said annular space forsealing said shaft with respect to said annular space and also forsealing said shaft with respect to said enclosing means, and stationaryhorizontal vanes supported by said enclosing means, said vanescorresponding in number and axial position to said mixing blades andbeing located just outwardly of the tips of said mixing blades, saidvanes being angularly spaced in their annular relationship to saidmixing blades.

6. Apparatus for carrying out a chemical reaction involving a pluralityof fluids and for inti- I mately mixing said fluids during said reactioncomprising stationary enclosing means forming a closed relatively largemixing and reaction zone. inlet means connected to said stationary meansfor continuously introducing thereto a fluid which participates in saidreaction, outlet means connected to said stationary means forcontinuously withdrawing reaction products therefrom, a rotatablestirrer shaft extending through said enclosing means into said zone,outwardly extending mixing blades carried by said shaftwithin said zonefor imparting turbulent and circulatory motion to the reaction mixturetherein, a

passageway in said shaft extending from an inlet point at the surfacethereof located outside said enclosing means axially along said shaftand then outwardly through said mixing blades to the ends thereof, amember surrounding said shaft and forming an annular space surroundingsaid inlet point, an inlet conduit connected to said member and to saidannular space, sealing means located outside said inlet point and saidannular space for sealing said shaft with respect to said annular space,common sealing means inside said inlet point and said annular space forsealing said shaft with respect to said annular space and also forsealing said shaft with respect to said enclosing means, meansassociated with said enclosing means and forming a second annular spacewhich surrounds said shaft and is in free communication with said zone,said common sealing means preventing fluid from passing upwardly alongsaid shaft from said second annular space, and an inletconduit connectedto said second annular space for supplying an inert fluid thereto andthence into said reaction zone thereby preventing the mixture in saidzone from contacting said common sealing means.

I MARYAN P. MATUSZAK.

